Zig-zag paper stacker



Dec. 10, 1968 J. F. ECKERT ET AL ZIGZAG PAPER STACKER Filed Sept. 8, 1965 INVENTORS:

JOHN F. ECKERT JOHN C. SIMS JR.

T fliw ATTORNEY United States Patent 3,415,507 ZIG-ZAG PAPER STACKER John F. Eckert, Maiden, and John C. Sims, Jr., Sudbury,

Mass., assignors, by mesne assignments, to Mohawk Data Science Corporation, East Herkimer, N.Y., a corporation of New York Filed Sept. 8, 1965, Ser. No. 485,828 2 Claims. (Cl. 270-61) ABSTRACT OF THE DISCLOSURE A continuous web of pre-folded forms is stacked in its original folded condition after having been run through a processing machine, such as :a printer, by a device having a vertically oriented throat, a guide plate located above the throat and a stacking platform located adjacent to and even with or below the throat. Feeding means forces an unfolded portion of the web upwardly through the throat and along the guide plate, which is inclined away from the stacking platform, whereby the weight of the web already on the platform pulls the upwardly travelling portion onto the top of the stack, causing it to assume its prefolded condition. A deflector is positioned at the top of the guide plate less than two formlengths away from the stacking platform to assist gravity in directing the web onto the stack.

This invention relates to devices for stacking paper and, in particular, to devices for refolding continuously folded, flat form paper as the paper is ejected by a printer.

Continuously folded paper (sometimes referred to as fan-folded paper) is commonly used as the output medium of a data processing system. This paper has preperforated fold lines which determine the positions of the folds. The paper is ordinarily supplied from a stack below a printing station and is fed incrementally for line-by-line printing. The paper leaving the printing station is ordinarily fed to the rear of the printer and allowed to fall and refold into a stack. This technique presents several problems. First, although the paper supply can be loaded from the front of the machine, and the copy viewed as it is printed, the stack of printed paper is formed behind the machine and is neither convenient to the operator nor does it permit the machine to be rack mounted or located against a wall. Second, the rear stack involves a rather long paper path causing the paper to develop a considerable static electric charge which causes it to stick to itself and adjacent objects. thus preventing stacking from taking place. Third, even if the static charge is eliminated by ion generators or other means, the long rear path often requires additional paper drive tractors to pull the paper back to the stacking location and active folding mechanisms to insure proper folding. Obviously all of these difficulties are further compounded as the speed of the printer is increased.

An object of the present invention is to overcome these diificulties by stacking the paper above and in front of the printing station by means of a simple arrangement of guides.

Another object of the present invention is to make use of guides whose proportions depend upon the size of the paper to be folded.

A further object is to provide a device for stacking paper at the front of a printer where it is convenient to the operator.

A still further object is to provide a device for stacking continuously folded paper which does not require an active mechanism to coerce the paper into the desired stacking configuration.

ice

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawmgs:

FIG. 1 is an isometric diagram showing the inventive paper stacker; and

FIGS. 2 and 3 are side views of the paper stacker showing the configuration of the paper during phases of the stacking operation.

Referring to FIGS. 1, 2 and 3, continuously folded paper 1 is drawn from a supply (not shown) upward toward a printing station consisting of a print roll 3 and a plurality of print hammers 5. The printing station is shown functionally and without detail because it does not form a part of the present invention. However, a suitable printing station is shown in US. Patent No. 2,940,- 385 which was issued to F. R. House on June 14, 1960.

In the preferred embodiment of the invention, marginally punched paper is used in conjunction with paper feed tractors, although unpunched, platen-fed paper could obviously be substituted. A pair of tractor assemblies 7, one on each side of the device, are incrementally activated as each line of printing is completed to draw the paper 1 up past the printing station, and into a narrow guide throat between a back plate 9 and a front plate 11. The distance between the plates is relatively small (e.g. M1"), constraining the paper so that it cannot fold along the perforated fold lines. At least the uppermost portion of the tractors is adjacent to the front plate to prevent folding in the region between the front plate and the printing station; this region being provided to enable the operator to view the printed paper before it is stacked.

The paper emerging from the throat between the back plate 9 and front plate 11 is then folded into a stack upon a support plate 13 located between two side guides 15, only one of which is shown in FIG. 1..

The back plate 9 extends above the front plate 11 by at least one form length (the distance between fold lines), and the top portion 17 of the back plate is curved or slanted to turn the forms forward for folding. For versatility, the top portion 17 is adjustably mounted to the remainder of the back plate 9 by the use of connectors 19 in conjunction with slots 21 in the back plate.

The paper naturally tends to refold in alternate directions corresponding to the folds that existed in the supply stack. FIGS. 2 and 3 illustrate the refolding action for both directions of preferential fold.

In FIG. 2, the paper is forced upward by the tractors 7 until the edge 23 of a previous fold reaches and is pushed forward (to the left) by the curved plate 17. The paper then falls over to assume the position illustrated by the dashed lines in FIG. 2. Turning now to FIG. 3, the falling paper (solid line) begins to reverse-fold at fold line 27. As the tractors continue to feed the paper, the fold line becomes more pronounced as shown by the dashed lines, followed by the dotted lines. When this fold is complete, the action shown in FIG. 2 re-occurs to for-m the next fold.

Thus, the present invention provides for accurate stacking of continuously folded forms above the printing station. The stacking process requires no active form-orienting mechanisms, but is accomplished by gravity under the control of the inventive arrangement of guides or plates. While the preferred embodiment of the invention is shown in connection with a printing station, the invention can obviously be practiced in any environment.

While the invention has been particularly shown and described =with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein Without departing from the spirit and scope of the invention.

What is claimed is:

1. Apparatus for stacking a web of continuous, prefolded forms comprising, in combination:

a substantially horizontal stacking platform;

a web guiding throat mounted substantially perpendicular to the surface of said platform and contiguous with one side thereof, said throat opening at a level above said platform;

means for feeding an unfolded portion of said web through said throat, whereby said web exits from said throat travelling upward and away from said platform in a direction substantially perpendicular thereto;

a guide plate mounted above the opening of said throat for guiding the travel of said web in said upward direction; and

a deflecting member on said plate spaced from the opening of said throat by a distance at least equal to the distance between folds in said web, said member being constructed and arranged to divert said web away from said plate, whereby every second fold in said web is driven against said deflecting member and the two portions of said web joined at said fold are caused to fall away from said plate and onto the portion of said web stacked on said stacking platform.

2. The apparatus set forth in claim 1, further comprismeans for adjusting the position of said deflecting member with respect to said plate to enable handling of dilferent form sizes.

References Cited UNITED STATES PATENTS 3,190,639 6/1965 Johnson et a1. 270-61 EUGENE R. CAPOZIO, Primary Examiner.

0 P. V. WILLIAMS, Assistant Examiner. 

